<script setup>
import { ref } from "vue";

// 图片列表
// const imageList = [
//   "https://yanxuan-item.nosdn.127.net/d917c92e663c5ed0bb577c7ded73e4ec.png",
//   "https://yanxuan-item.nosdn.127.net/e801b9572f0b0c02a52952b01adab967.jpg",
//   "https://yanxuan-item.nosdn.127.net/b52c447ad472d51adbdde1a83f550ac2.jpg",
//   "https://yanxuan-item.nosdn.127.net/f93243224dc37674dfca5874fe089c60.jpg",
//   "https://yanxuan-item.nosdn.127.net/f881cfe7de9a576aaeea6ee0d1d24823.jpg"
// ]
defineProps({
  imageList:{
    type:Array,
    default:()=>[]
  }
})





//1.小图切换大图显示
const activeIndex=ref(0)
const enterhandler=(i)=>{
  activeIndex.value=i
}


//2.获取鼠标相对位置
import { useMouseInElement } from "@vueuse/core"
import { watch } from "vue";
const target=ref(null)
const left =ref(0)
const top=ref(0)
const positionX=ref(0)
const positionY=ref(0)
const { elementX,elementY,isOutside}=useMouseInElement(target)
//3.控制滑块跟随鼠标移动，（监听elementX/Y变化，一旦变化，重新设置left/top）
watch([elementX,elementY],()=>{
    //横向
    if(elementX.value>100&&elementX.value<300){
      //正常
       left.value=elementX.value-100
    }
    //纵向
    if(elementY.value>100&&elementY.value<300){
      //正常
       top.value=elementY.value-100
    }


    //处理边界
    if(elementX.value<=100){
      left.value=0
    }
    if(elementX.value>=300){
      left.value=200
    }
    if(elementY.value<=100){
      top.value=0
    }
    if(elementY.value>=300){
      top.value=200
    }
    //处理滑块超出边界
    if(isOutside.value
    ){
      left.value=0
      top.value=0
    }
//控制大图的显示,根据滑块的位置，计算大图的位置，2倍负移动
    positionX.value=-left.value*2
    positionY.value=-top.value*2
})







</script>


<template>
  <div class="goods-image">
    <!-- 左侧大图-->
    <div class="middle" ref="target">
      <img :src="imageList[activeIndex]" alt="" />
      <!-- 蒙层小滑块 -->
      <div class="layer" v-show="!isOutside" :style="{ left: left+'px', top: top+'px' }"></div>
    </div>
    <!-- 小图列表 mouseenter鼠标引入切换大图,active激活图片-->
    <ul class="small">
      <li v-for="(img, i) in imageList" :key="i" @mouseenter="enterhandler(i)" :class="{ active: i === activeIndex }">
        <img :src="img" alt="" />
      </li>
    </ul>
    <!-- 放大镜大图 -->
    <div class="large" v-show="!isOutside" :style="[
      {
        backgroundImage: `url(${imageList[activeIndex]})`,
        backgroundPositionX: positionX+`px`,
        backgroundPositionY: positionY+`px`,
      },
    ]"></div>
  </div>
</template>

<style scoped lang="scss">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;

  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
  }

  .large {
    position: absolute;
    top: 0;
    left: 412px;
    width: 400px;
    height: 400px;
    z-index: 500;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    background-repeat: no-repeat;
    // 背景图:盒子的大小 = 2:1  将来控制背景图的移动来实现放大的效果查看 background-position
    background-size: 800px 800px;
    background-color: #f8f8f8;
  }

  .layer {
    width: 200px;
    height: 200px;
    background: rgba(0, 0, 0, 0.2);
    // 绝对定位 然后跟随咱们鼠标控制left和top属性就可以让滑块移动起来
    left: 0;
    top: 0;
    position: absolute;
  }

  .small {
    width: 80px;

    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;

      &:hover,
      &.active {
        border: 2px solid $xtxColor;
      }
    }
  }
}
</style>